Download habitat hair follicle half-life halogen haploid hardness harmonics

habitat
place where an organism lives out its life.
hair follicle
narrow cavities in the dermis from which hair grows.
half-life
halogen
The time required for one-half of a radioisotope’s nuclei to
decay into its products.
A highly reactive group 7A element.
haploid
cell with one of each kind of chromosome; is said to contain a
haploid or n, number of chromosomes.
hardness
Measure of how easily a mineral can be scratched, which is
determined by the arrangement of a mineral’s atoms.
harmonics
Higher frequencies, which are odd-numbered multiples of the
fundamental frequency; give certain musical instruments their
own unique timbre.
heat
A form of energy that flows from a warmer object to a cooler
object.
hemoglobin
iron-containing protein molecule in red blood cells that binds to
oxygen and carries it from the lungs to the body’s cells.
heredity
heterogeneous mixture
passing on of characteristics from parents to offspring.
One that does not have a uniform composition and in which the
individual substances remain distinct.
heterotrophs
organisms that cannot make their own food and must feed on
other organisms for energy and nutrients.
hibernation
state of reduced metabolism occurring in animals that sleep
during parts of cold winter months; an animal’s temperature
drops, oxygen consumption decreases, and breathing rate
declines.
highlands
Light-colored, mountainous, heavily cratered areas of the
Moon, composed mostly of lunar breccias.
homeostasis
organism’s regulation of its internal environment to maintain
conditions suitable for survival; a characteristic of all living
things.
hominids
Group of upright, bipedal primates, including Homo sapiens.
Homo sapiens
Species to which humans belong.
homogeneous mixture
One that has a uniform composition throughout and always has
a single phase; also called a solution.
homozygous
hormone
host cell
when there are two identical alleles for a trait.
chemical produced in one part of an organism and transported
to another part, where it causes a physiological change.
living cell in which a virus replicates.
hot spot
Unusually hot area in Earth’s mantle that is stationary for long
periods of time, where high-temperature plumes of mantle
material rise toward the surface.
hot spring
Thermal spring with temperatures higher than that of the
human body.
human genome
map of the approximately 80 000 genes on 46 human
chromosomes that when mapped and sequenced, may provide
information on the treatment or cure of genetic disorders.
humidity
Amount of water vapor in the air.
hybrid
offspring formed by parents having different forms of a trait.
hydrate
A compound that has a specific number of water molecules
bound to its atoms.
hydrocarbon
Simplest organic compound composed only of the elements
carbon and hydrogen.
hydrogen bond
weak chemical bond formed by the attraction of positively
charged hydrogen atoms to other negatively charged atoms.
hydrolysis
hydrosphere
Chemical reaction of water with other substances.
All the water in Earth’s oceans, lakes, seas, rivers, and glaciers
plus all the water in the atmosphere.
hydrothermal vent
hygrometer
Hot-water, deep-sea vent that has the energy and nutrients
needed for the beginnings of life.
Weather instrument used to measure relative humidity.
hypertonic solution
in cells, solution in which the concentration of dissolved
substances outside the cell is higher than the concentration inside
the cell; causes a cell to shrink as water leaves the cell.
hypothalamus
portion of the brain that connects the endocrine and nervous
systems, and controls the pituitary gland by sending messages to
the pituitary, which then releases its own chemicals or stimulates
other glands to release chemicals.
hypothesis
explanation for a question or a problem that can be formally
tested.
hypotonic solution
in cells, solution in which the concentration of dissolved
substances is lower in the solution outside the cell than the
concentration inside the cell; causes a cell to swell and possibly
burst as water enters the cell.